“Both statewide and in the region, we’ve been seeing an increased number of cases,” said Dr. Sarah Haessler, an infectious disease specialist at Baystate Medical Center in Springfield.

The Centers for Disease Control in Atlanta report thats Massachusetts is among the hardest-hit states. A public health emergency has been declared in Boston.

In Northampton, three to five people a day come into Cooley Dickinson Hospital in complaining of flu-like symptoms, according to Linda Riley, infection prevention nurse at the hospital.

Riley said seven of those people were admitted to her hospital last week. By Wednesday of this week, four more were admitted.

“This is the most we’ve seen all year long,” said Carol Wojnarowski, infection control manager at Holyoke Medical Center.

In an effort to stop the spread of the illness, Baystate is putting restrictions on visitors. “We are asking visitors not to bring family members under 14 years old,” said Haessler.

“If you are ill with influenza symptoms, please call the person (who is hospitalized) rather than visiting.

“If you have an appointment with a doctor, please don’t bring more than one support person, and leave the kids at home.”

By the end of 2012, 3,736 cases of flu had been confirmed in Massachusetts. The Centers for Disease Control will release numbers for the week ending Jan. 4 on Friday.

The good news is that most people can do something to avoid getting the flu.

First, get a flu shot. “Most of the influenza cases are due to the H3N2 virus, and that’s contained in the flu vaccine,” said Haessler. “It’s not a new strain. It has circulated around for the last couple of years, and that’s why the vaccine targets it.”

Other than that, wash hands frequently with soap and water or an alcohol-based hand rub, say these expert.

Keep hands away from the eyes, nose and mouth. “Studies have shown that people touch their faces up 2,000 times a day,” said Riley. “They do it unconsciously.”

“Avoid people with influenza symptoms,”said Haessler, “and stay home from work if you’re sick.”

Some people worry that there won’t be enough vaccine to go around. Not true, says Riley. “We have plenty,” she said.

People also fear that the flu shot itself will bring on a case of the flu. Also false, said Riley. “Sometimes people may feel achy or tired after they get the vaccines. “It’s usually your body making antibodies,” she said. “Your body makes antibodies if it sees the actual flu virus come along.” Even though the shot contains a dead virus instead of a live one, she said, the body gets ready to fight it.